CMS ECAL Barrel, Unit Cell Analysis for Basket Bottom Plate

Bottom plates of modular containers ( baskets) in CMS ECAL Barrel are perforated with a large number of holes needed to introduce optical fibres and to support set pins. The weakening of the plates due to the holes was studied by FEM ( unit cell analyses) in comparison to complementary analytical methods, and equivalent orthotropic stiffness parameters were obtained. A link was established between the global ( macro) stress states of the plates and local ( micro) stress states along the circumferences of the holes.